JPH10185675A - Sound pressure sensor for ultrasonic cleaning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct the sensitivity by changing an amplification degree of a variable amplifying part even in the case where unevenness exists in the sensitivity of a piezoelectric element used for a wave detecting unit. SOLUTION: An ultrasonic wave transmitted in a sensitive piece 11 enters a pick-up part 22, and a piezoelectric element generates the high frequency voltage (a) proportional to magnitude of the ultrasonic wave. This voltage (a) is detected through a diode 32, and the wave detecting signal (b), which is wave detected, is input to an amplifier 35. The wave detecting signal (a) is amplified by an amplifier 35. Amplification degree of the signal (a) can be changed by a feedback resistor 37. The signal C output from the amplifier 35 is output to a meter 11, and an indicator of the meter 11 is sensed in proportion to the ultrasonic wave. Since the amplification degree of the amplifier 35 can be changed, even in the case where unevenness exists in the characteristic of the pick-up part 22, which is formed of the diode 32, amplification degree can be changed by the external operation so as to absorb the unevenness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound pressure sensor for an ultrasonic cleaning device for measuring the sound pressure of ultrasonic waves of an ultrasonic cleaning device used for applying ultrasonic vibration to a cleaning liquid for cleaning an object to be cleaned. .

[0002]

2. Description of the Related Art For example, in a liquid crystal manufacturing apparatus or a semiconductor manufacturing apparatus, there is a process required to clean an object to be cleaned such as a glass substrate for a liquid crystal or a semiconductor wafer with high cleanliness. As a method of cleaning the object to be cleaned, there are a dip method in which a plurality of objects to be cleaned are immersed in a cleaning liquid, and a single-wafer method in which the cleaning liquid is sprayed toward the object to be cleaned to wash one by one. In addition to obtaining high cleanliness, a single-wafer method which is advantageous in terms of cost is often used.

[0003] As one of the single-wafer methods, a cleaning method has been put to practical use in which ultrasonic vibration is applied to a cleaning liquid sprayed on a cleaning object to thereby efficiently remove fine particles from the cleaning object by vibrating action. ing.

The vibration applied to the cleaning liquid has conventionally been 20 to 50 k.
Hz, but recently 600-2000 kHz
An ultrasonic cleaning device that applies a sound wave in the ultra-ultrasonic band of about z has been developed.

The ultrasonic cleaning apparatus has an apparatus main body, and the apparatus main body is provided with a diaphragm on which a vibrator is attached. An ultrasonic oscillator is connected to the vibrator. The ultrasonic oscillator outputs power of a predetermined frequency and applies the power to the vibrator. Accordingly, the vibrator vibrates ultrasonically, and the vibrating plate is linked to the ultrasonic vibration, and the vibrating plate applies ultrasonic vibration to the cleaning liquid.

[0006] In such an ultrasonic cleaning apparatus, the sound pressure of the ultrasonic wave in the apparatus is measured using a sound pressure sensor. This sound pressure sensor uses a piezoelectric element for detecting an ultrasonic wave as a pickup, detects a voltage signal proportional to the magnitude of the ultrasonic wave detected by the pickup with a detection circuit, and uses the voltage signal detected by the detection circuit to measure the voltage signal. -You are trying to shake the data.

[0007]

However, since the sensitivity of the pickup used in this sound pressure sensor varies, it is necessary to multiply the voltage signal detected by the detection circuit by a coefficient to correct the sensitivity. I have to.

However, if the coefficient is fixed as described above, there is a problem that the sensitivity cannot be accurately corrected when the pickup is replaced. The present invention has been made in view of the above points, and an object of the present invention is to provide a sound pressure sensor for an ultrasonic cleaning device that can perform sensitivity correction even when the sensitivity of a pickup used for the sound pressure sensor varies. To provide.

[0009]

According to a first aspect of the present invention, there is provided a sound pressure sensor for an ultrasonic cleaning device, comprising: a receiving unit for receiving an ultrasonic wave;
A detection unit for detecting the ultrasonic signal received by the reception unit, a variable amplification unit for variably amplifying the signal detected by the detection unit, and a display unit for displaying the sound pressure variably amplified by the variable amplification unit And characterized in that:

With this configuration, even if the sensitivity of the piezoelectric element used as the detection unit varies, the sensitivity can be corrected by varying the amplification degree of the variable amplification unit. The variable amplifying unit used in the sound pressure sensor for an ultrasonic cleaning apparatus according to the second aspect is capable of changing the amplification degree by an external operation.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 illustrates a sound pressure sensor 10 for an ultrasonic cleaning device. In FIG. 1, reference numeral 11 denotes a sensitive piece as a receiving unit that receives ultrasonic waves. A piezoelectric element to be described later is pressed against the end face of the sensitive piece 11.

Numeral 12 denotes a grip for the operator to grip the sensor. A detection circuit and a sensitivity correction circuit are built in the grip portion 12. The gripper 12 is connected to a meter 14 via a cable 13. This mail
The sound pressure is displayed on the pointer 14 with a pointer.

Next, referring to FIG. 2, a block diagram of an electric circuit built in the grasping unit 12 is shown. In FIG. 2, 1
Reference numeral 1 denotes a receiving unit that receives an ultrasonic wave. The output of the receiving unit 11 is input to the pickup unit 22. The ultrasonic signal is detected by the pickup unit 22.

The ultrasonic signal detected by the pickup unit 22 is output to a sensitivity correction circuit 23. The receiving unit 11, the pickup unit 22, and the sensitivity correction circuit 23
Will be described later with reference to FIG.

In FIG. 3, reference numeral 11 denotes a sensitive piece, through which ultrasonic waves propagate. A piezoelectric ceramic 21 is pressed against the end of the sensitive piece 11.
A resistor 31 is connected to both ends of the piezoelectric ceramic 21. One end of the resistor 31 is connected to a diode 32 and a capacitor 33. A resistor 34 is connected to both ends of the capacitor 33.

Further, the non-ground side terminal of the resistor 34 is input to the + terminal of the amplifier circuit 35. This amplifier circuit 35 is grounded via a resistor 36. Further, the output of the amplifier circuit 35 is connected to a non-ground side terminal of the resistor 36 via a feedback resistor 37 which is a variable resistor. The feedback resistor 37 can be changed by an external operation.

Next, a detailed configuration of the sound pressure sensor for the ultrasonic cleaning device will be described with reference to FIG. FIG. 4 is a sectional view of the sound pressure sensor 10. As shown in FIG.
One end has a bottom 11a in the form of a rotor.

The grip 12 has a cylindrical shape. Further, a chamber 41 for accommodating the piezoelectric ceramic 21 is provided at one end of the grip portion 12. At one end of the grip portion 12, the bottom 11a of the sensitive piece 11 is
The cover 42 is screwed in so as to press-contact.

Further, an amplification circuit 35 is built in the center of the grip 12. The piezoelectric ceramic 21 and the amplifier 35 are connected by an input cable 43.
A back cover 44 is fitted into the other end of the grip 12. The back cover 44 is provided with a through hole 45.

An output cable 46 is provided through the through hole 45.
Is connected to the meter 14. Next, the operation of the embodiment of the present invention configured as described above will be described. This ultrasonic cleaning device sound pressure sensor 10 is a device for cleaning an object to be cleaned such as a wafer using ultrasonic waves, like an ultrasonic cleaning device, and detects the sound pressure of ultrasonic waves generated by the ultrasonic cleaning device. It is a sensor for detecting.

That is, in such an ultrasonic cleaning apparatus, the operator grips the gripper 12 and arranges the tip of the sensitive piece 11 so as to be in the path of the ultrasonic wave to be measured.

Hereinafter, description will be made with reference to FIG. In FIG. 3, the ultrasonic wave propagating through the sensitive piece 11 is incident on the pickup unit 22. The pickup section 22 is a piezoelectric element that generates a high-frequency voltage a proportional to the size of the ultrasonic wave.

This high frequency voltage a is detected via a diode 32. The detected detection signal b is supplied to the amplifier 35
Is input to Then, the detection signal a is amplified by the amplifier 35.

The degree of amplification of the detection signal a can be changed by a feedback resistor 37. And this amplifier 3
The signal c output from 5 is output to the meter 11.
In this meter 11, the meter is set to be proportional to the ultrasonic wave.
The pointer of data 11 swings.

Incidentally, in the amplifier 35, the amplification degree of the amplifier 35 can be made variable by making the feedback resistor 37 variable. Thus, the amplifier 3
Even if the characteristics of the pickup unit 22 composed of the diode 32 vary by making the amplification degree 5 variable, the variation can be absorbed by making the amplification degree variable by an external operation. Can be.

[0026]

According to the first and second aspects of the present invention, even if the sensitivity of the pickup varies, the ultrasonic cleaning which can accurately measure the size of the ultrasonic wave used in the ultrasonic cleaning apparatus can be performed. An apparatus sound pressure sensor can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view of a sound pressure sensor for an ultrasonic cleaning device according to an embodiment of the present invention.

FIG. 2 is a block diagram of an electric circuit built in the sound pressure sensor.

FIG. 3 is a detailed circuit diagram of the electric circuit.

FIG. 4 is a sectional view of a sound pressure sensor for an ultrasonic cleaning device.

[Explanation of symbols]

11 ... sensitive piece, 12 ... gripping part, 13 ... cable, 14 ...
Meter, 22: pickup unit, 23: sensitivity correction circuit,
31, 34, 36: resistor, 32: diode, 33: capacitor, 35: amplifier circuit, 37: feedback resistor.

Claims (2)

[Claims] A receiving unit that receives an ultrasonic wave; a pickup unit that converts an ultrasonic wave received by the receiving unit into an electric signal; a detection unit that detects an ultrasonic signal output from the pickup unit; A variable amplifier for variably amplifying the signal detected by the detector; and a display for displaying the sound pressure of the ultrasonic wave according to the signal variably amplified by the variable amplifier. Sound pressure sensor for sonic cleaning equipment. 2. The sound pressure sensor for an ultrasonic cleaning device according to claim 1, wherein said variable amplifying unit can vary the degree of amplification by an external operation.